干货 各种使用"/>
老司机转发的干货 各种使用
总结了几个月的东西终于能和大家分享了，不多说，直接看东西！
1、禁止手机睡眠
| 1 | [UIApplication sharedApplication].idleTimerDisabled = YES; |
2、隐藏某行cell
| 1 2 3 4 5 6 7 8 9 10 11 | - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath { // 如果是你需要隐藏的那一行，返回高度为0 if (indexPath.row == YouWantToHideRow) return 0; return 44; } // 然后再你需要隐藏cell的时候调用 [self.tableView beginUpdates]; [self.tableView endUpdates]; |
3、禁用button高亮
| 1 2 3 | button.adjustsImageWhenHighlighted = NO; 或者在创建的时候 UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom]; |
4、tableview遇到这种报错failed to obtain a cell from its dataSource
是因为你的cell被调用的早了。先循环使用了cell，后又创建cell。顺序错了
可能原因：1、xib的cell没有注册 2、内存中已经有这个cell的缓存了(也就是说通过你的cellId找到的cell并不是你想要的类型)，这时候需要改下cell的标识
5、cocoa pods报这个错误：unable to access ‘.git/': Operation timed out after 0 milliseconds with 0 out of 0 bytes received
解决办法：原因可能是网络问题，网络请求超时了，只需要重试就行了
6、cocoa pods 出现ERROR: While executing gem ... (Errno::EPERM)
解决办法：
7、动画切换window的根控制器
| 1 2 3 4 5 6 7 8 | // options是动画选项 [UIView transitionWithView:[UIApplication sharedApplication].keyWindow duration:0.5f options:UIViewAnimationOptionTransitionCrossDissolve animations:^{ BOOL oldState = [UIView areAnimationsEnabled]; [UIView setAnimationsEnabled:NO]; [UIApplication sharedApplication].keyWindow.rootViewController = [RootViewController new ]; [UIView setAnimationsEnabled:oldState]; } completion:^(BOOL finished) { }]; |
8、去除数组中重复的对象
| 1 | NSArray *newArr = [oldArr valueForKeyPath:@“@distinctUnionOfObjects.self"]; |
9、编译的时候遇到 no such file or directory: ／users／apple／XXX
是因为编译的时候，在此路径下找不到这个文件，解决这个问题，首先是是要检查缺少的文件是不是在工程中，如果不在工程中，需要从本地拖进去，如果发现已经存在工程中了，或者拖进去还是报错，这时候需要去build phases中搜索这个文件，这时候很可能会搜出现两个相同的文件，这时候，有一个路径是正确的，删除另外一个即可。如果删除了还是不行，需要把两个都删掉，然后重新往工程里拖进这个文件即可
10、iOS8系统中，tableView最好实现下-tableView: heightForRowAtIndexPath:这个代理方法，要不然在iOS8中可能就会出现显示不全或者无法响应事件的问题
11、iOS8中实现侧滑功能的时候这个方法必须实现，要不然在iOS8中无法侧滑
| 1 2 3 4 | // 必须写的方法，和editActionsForRowAtIndexPath配对使用，里面什么不写也行 - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath { } |
12、三个通知
NSSystemTimeZoneDidChangeNotification监听修改时间界面的两个按钮状态变化
UIApplicationSignificantTimeChangeNotification 监听用户改变时间 （只要点击自动设置按钮就会调用） NSSystemClockDidChangeNotification 监听用户修改时间（时间不同才会调用）
13、SDWebImage本地缓存有时候会害人。如果之前缓存过一张图片，即使下次服务器换了这张图片，但是图片url没换，用sdwebimage下载下来的还是以前那张,所以遇到这种问题，不要先去怼服务器，清空下缓存再试就好了。
14、上线前注意：
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1）、删掉代码中所有的测试代码
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2）、如果后台有审核模式，提醒后台开启此模式
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3）、主流程再跑一跑
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4）、全局搜索waring，检查所有标记waring的地方
15、跳进app权限设置
| 1 2 3 4 5 6 | // 跳进app设置 if (UIApplicationOpenSettingsURLString != NULL) { NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString]; [[UIApplication sharedApplication] openURL:url]; } } |
16、给一个view截图
| 1 2 3 4 | UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0.0); [view.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *img = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); |
17、开发中如果要动态修改tableView的tableHeaderView或者tableFooterView的高度，需要给tableView重新设置，而不是直接更改高度。正确的做法是重新设置一下tableView.tableFooterView = 更改过高度的view。为什么？其实在iOS8以上直接改高度是没有问题的，在iOS8中出现了contentSize不准确的问题，这是解决办法。
18、注意对象为nil的时候，调用此对象分类的方法不会执行
19、collectionView的内容小于其宽高的时候是不能滚动的，设置可以滚动：
| 1 2 | collectionView.alwaysBounceHorizontal = YES; collectionView.alwaysBounceVertical = YES; |
20、设置navigationBar上的title颜色和大小
| 1 | [self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}] |
21、颜色转图片
| 1 2 3 4 5 6 7 8 9 10 11 12 13 | + (UIImage *)cl_imageWithColor:(UIColor *)color { CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f); UIGraphicsBeginImageContext(rect.size); CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSetFillColorWithColor(context, [color CGColor]); CGContextFillRect(context, rect); UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return image; } |
22、view设置圆角
| 1 2 3 4 5 6 | #define ViewBorderRadius(View, Radius, Width, Color)\ \ [View.layer setCornerRadius:(Radius)];\ [View.layer setMasksToBounds:YES];\ [View.layer setBorderWidth:(Width)];\ [View.layer setBorderColor:[Color CGColor]] // view圆角 |
23、强／弱引用
| 1 2 | #define WeakSelf(type) __weak typeof(type) weak##type = type; // weak #define StrongSelf(type) __strong typeof(type) type = weak##type; // strong |
24、由角度转换弧度
| 1 | #define DegreesToRadian(x) (M_PI * (x) / 180.0) |
25、由弧度转换角度
| 1 | #define RadianToDegrees(radian) (radian*180.0)/(M_PI) |
26、获取图片资源
| 1 | #define GetImage(imageName) [UIImage imageNamed:[NSString stringWithFormat:@"%@",imageName]] |
27、获取temp
| 1 | #define PathTemp NSTemporaryDirectory() |
28、获取沙盒 Document
| 1 | #define PathDocument [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject] |
29、获取沙盒 Cache
| 1 | #define PathCache [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject] |
30、GCD代码只执行一次
| 1 | #define kDISPATCH_ONCE_BLOCK(onceBlock) static dispatch_once_t onceToken; dispatch_once(&onceToken, onceBlock); |
31、自定义NSLog
| 1 2 3 4 5 | #ifdef DEBUG #define NSLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__) #else #define NSLog(...) #endif |
32、Font
| 1 2 3 4 5 | #define FontL(s) [UIFont systemFontOfSize:s weight:UIFontWeightLight] #define FontR(s) [UIFont systemFontOfSize:s weight:UIFontWeightRegular] #define FontB(s) [UIFont systemFontOfSize:s weight:UIFontWeightBold] #define FontT(s) [UIFont systemFontOfSize:s weight:UIFontWeightThin] #define Font(s) FontL(s) |
33、FORMAT
| 1 | #define FORMAT(f, ...) [NSString stringWithFormat:f, ## __VA_ARGS__] |
34、在主线程上运行
| 1 | #define kDISPATCH_MAIN_THREAD(mainQueueBlock) dispatch_async(dispatch_get_main_queue(), mainQueueBlock); |
35、开启异步线程
| 1 | #define kDISPATCH_GLOBAL_QUEUE_DEFAULT(globalQueueBlock) dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), globalQueueBlocl); |
36、通知
| 1 2 3 | #define NOTIF_ADD(n, f) [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(f) name:n object:nil] #define NOTIF_POST(n, o) [[NSNotificationCenter defaultCenter] postNotificationName:n object:o] #define NOTIF_REMV() [[NSNotificationCenter defaultCenter] removeObserver:self] |
37、随机颜色
| 1 2 3 4 5 6 7 | + (UIColor *)RandomColor { NSInteger aRedValue = arc4random() % 255; NSInteger aGreenValue = arc4random() % 255; NSInteger aBlueValue = arc4random() % 255; UIColor *randColor = [UIColor colorWithRed:aRedValue / 255.0f green:aGreenValue / 255.0f blue:aBlueValue / 255.0f alpha:1.0f]; return randColor; } |
38、获取window
| 1 2 3 4 5 6 7 8 9 10 11 12 | +(UIWindow*)getWindow { UIWindow* win = nil; //[UIApplication sharedApplication].keyWindow; for (id item in [UIApplication sharedApplication].windows) { if ([item class] == [UIWindow class]) { if (!((UIWindow*)item).hidden) { win = item; break ; } } } return win; } |
39、修改textField的placeholder的字体颜色、大小
| 1 2 | [textField setValue:[UIColor redColor] forKeyPath:@ "_placeholderLabel.textColor" ]; [textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@ "_placeholderLabel.font" ]; |
40、统一收起键盘
| 1 | [[[UIApplication sharedApplication] keyWindow] endEditing:YES]; |
41、控制屏幕旋转，在控制器中写
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 | /** 是否支持自动转屏 */ - (BOOL)shouldAutorotate { return YES; } /** 支持哪些屏幕方向 */ - (UIInterfaceOrientationMask)supportedInterfaceOrientations { return UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight; } /** 默认的屏幕方向（当前ViewController必须是通过模态出来的UIViewController（模态带导航的无效）方式展现出来的，才会调用这个方法） */ - (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation { return UIInterfaceOrientationLandscapeLeft | UIInterfaceOrientationLandscapeRight; } |
42、获取app缓存大小
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | - (CGFloat)getCachSize { NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize]; //获取自定义缓存大小 //用枚举器遍历 一个文件夹的内容 //1.获取 文件夹枚举器 NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@ "Library/Caches" ]; NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath]; __block NSUInteger count = 0; //2.遍历 for (NSString *fileName in enumerator) { NSString *path = [myCachePath stringByAppendingPathComponent:fileName]; NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil]; count += fileDict.fileSize; //自定义所有缓存大小 } // 得到是字节 转化为M CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024; return totalSize; } |
43、清理app缓存
| 1 2 3 4 5 6 7 8 9 10 11 | - (void)handleClearView { //删除两部分 //1.删除 sd 图片缓存 //先清除内存中的图片缓存 [[SDImageCache sharedImageCache] clearMemory]; //清除磁盘的缓存 [[SDImageCache sharedImageCache] clearDisk]; //2.删除自己缓存 NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@ "Library/Caches" ]; [[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil]; } |
44、模型转字典
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 | static NSSet *classes; - (NSMutableDictionary *)getParameterDictionary { NSMutableDictionary *dict = [NSMutableDictionary dictionary]; Class c = self.class; while (c) { unsigned count; objc_property_t *properties = class_copyPropertyList([c class], &count); for (int i = 0; i < count; i++) { NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])]; dict[key] = [self valueForKey:key]; } free(properties); // 获得父类 c = class_getSuperclass(c); if ([self isClassFromFoundation:c]) break ; } return dict; } - (BOOL)isClassFromFoundation:(Class)c { if (c == [NSObject class] || c == [NSManagedObject class]) return YES; __block BOOL result = NO; [[self foundationClasses] enumerateObjectsUsingBlock:^(Class foundationClass, BOOL *stop) { if ([c isSubclassOfClass:foundationClass]) { result = YES; *stop = YES; } }]; return result; } - (NSSet *)foundationClasses { if (classes == nil) { // 集合中没有NSObject，因为几乎所有的类都是继承自NSObject，具体是不是NSObject需要特殊判断 classes = [NSSet setWithObjects: [NSURL class], [NSDate class], [NSValue class], [NSData class], [NSError class], [NSArray class], [NSDictionary class], [NSString class], [NSAttributedString class], nil]; } return classes; } |
45、交换两个方法实现
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | Class aClass = [self class]; SEL originalSelector = @selector(viewWillAppear:); SEL swizzledSelector = @selector(xxx_viewWillAppear:); Method originalMethod = class_getInstanceMethod(aClass, originalSelector); Method swizzledMethod = class_getInstanceMethod(aClass, swizzledSelector); BOOL didAddMethod = class_addMethod(aClass, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod)); if (didAddMethod) { class_replaceMethod(aClass, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod)); } else { method_exchangeImplementations(originalMethod, swizzledMethod); } |
46、打印百分号和引号
| 1 2 | NSLog(@ "%%" ); NSLog(@ "\"" ); |
47、几个常用权限判断
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | if ([CLLocationManager authorizationStatus] ==kCLAuthorizationStatusDenied) { NSLog(@ "没有定位权限" ); } AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo]; if (statusVideo == AVAuthorizationStatusDenied) { NSLog(@ "没有摄像头权限" ); } //是否有麦克风权限 AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio]; if (statusAudio == AVAuthorizationStatusDenied) { NSLog(@ "没有录音权限" ); } [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) { if (status == PHAuthorizationStatusDenied) { NSLog(@ "没有相册权限" ); } }]; |
48、获取手机型号
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 | + (NSString *)getDeviceInfo { struct utsname systemInfo; uname(&systemInfo); NSString *platform = [NSString stringWithCString:systemInfo.machine encoding:NSASCIIStringEncoding]; if ([platform isEqualToString:@ "iPhone1,1" ]) return @ "iPhone 2G" ; if ([platform isEqualToString:@ "iPhone1,2" ]) return @ "iPhone 3G" ; if ([platform isEqualToString:@ "iPhone2,1" ]) return @ "iPhone 3GS" ; if ([platform isEqualToString:@ "iPhone3,1" ]) return @ "iPhone 4" ; if ([platform isEqualToString:@ "iPhone3,2" ]) return @ "iPhone 4" ; if ([platform isEqualToString:@ "iPhone3,3" ]) return @ "iPhone 4" ; if ([platform isEqualToString:@ "iPhone4,1" ]) return @ "iPhone 4S" ; if ([platform isEqualToString:@ "iPhone5,1" ]) return @ "iPhone 5" ; if ([platform isEqualToString:@ "iPhone5,2" ]) return @ "iPhone 5" ; if ([platform isEqualToString:@ "iPhone5,3" ]) return @ "iPhone 5c" ; if ([platform isEqualToString:@ "iPhone5,4" ]) return @ "iPhone 5c" ; if ([platform isEqualToString:@ "iPhone6,1" ]) return @ "iPhone 5s" ; if ([platform isEqualToString:@ "iPhone6,2" ]) return @ "iPhone 5s" ; if ([platform isEqualToString:@ "iPhone7,1" ]) return @ "iPhone 6 Plus" ; if ([platform isEqualToString:@ "iPhone7,2" ]) return @ "iPhone 6" ; if ([platform isEqualToString:@ "iPhone8,1" ]) return @ "iPhone 6s" ; if ([platform isEqualToString:@ "iPhone8,2" ]) return @ "iPhone 6s Plus" ; // 日行两款手机型号均为日本独占，可能使用索尼FeliCa支付方案而不是苹果支付 if ([platform isEqualToString:@ "iPhone9,1" ]) return @ "国行、日版、港行iPhone 7" ; if ([platform isEqualToString:@ "iPhone9,2" ]) return @ "港行、国行iPhone 7 Plus" ; if ([platform isEqualToString:@ "iPhone9,3" ]) return @ "美版、台版iPhone 7" ; if ([platform isEqualToString:@ "iPhone9,4" ]) return @ "美版、台版iPhone 7 Plus" ; if ([platform isEqualToString:@ "iPhone8,4" ]) return @ "iPhone SE" ; if ([platform isEqualToString:@ "iPod1,1" ]) return @ "iPod Touch 1G" ; if ([platform isEqualToString:@ "iPod2,1" ]) return @ "iPod Touch 2G" ; if ([platform isEqualToString:@ "iPod3,1" ]) return @ "iPod Touch 3G" ; if ([platform isEqualToString:@ "iPod4,1" ]) return @ "iPod Touch 4G" ; if ([platform isEqualToString:@ "iPod5,1" ]) return @ "iPod Touch 5G" ; if ([platform isEqualToString:@ "iPad1,1" ]) return @ "iPad 1G" ; if ([platform isEqualToString:@ "iPad2,1" ]) return @ "iPad 2" ; if ([platform isEqualToString:@ "iPad2,2" ]) return @ "iPad 2" ; if ([platform isEqualToString:@ "iPad2,3" ]) return @ "iPad 2" ; if ([platform isEqualToString:@ "iPad2,4" ]) return @ "iPad 2" ; if ([platform isEqualToString:@ "iPad2,5" ]) return @ "iPad Mini 1G" ; if ([platform isEqualToString:@ "iPad2,6" ]) return @ "iPad Mini 1G" ; if ([platform isEqualToString:@ "iPad2,7" ]) return @ "iPad Mini 1G" ; if ([platform isEqualToString:@ "iPad3,1" ]) return @ "iPad 3" ; if ([platform isEqualToString:@ "iPad3,2" ]) return @ "iPad 3" ; if ([platform isEqualToString:@ "iPad3,3" ]) return @ "iPad 3" ; if ([platform isEqualToString:@ "iPad3,4" ]) return @ "iPad 4" ; if ([platform isEqualToString:@ "iPad3,5" ]) return @ "iPad 4" ; if ([platform isEqualToString:@ "iPad3,6" ]) return @ "iPad 4" ; if ([platform isEqualToString:@ "iPad4,1" ]) return @ "iPad Air" ; if ([platform isEqualToString:@ "iPad4,2" ]) return @ "iPad Air" ; if ([platform isEqualToString:@ "iPad4,3" ]) return @ "iPad Air" ; if ([platform isEqualToString:@ "iPad4,4" ]) return @ "iPad Mini 2G" ; if ([platform isEqualToString:@ "iPad4,5" ]) return @ "iPad Mini 2G" ; if ([platform isEqualToString:@ "iPad4,6" ]) return @ "iPad Mini 2G" ; if ([platform isEqualToString:@ "i386" ]) return @ "iPhone Simulator" ; if ([platform isEqualToString:@ "x86_64" ]) return @ "iPhone Simulator" ; return platform; } |
49、长按复制功能
| 1 2 3 4 5 6 7 8 9 10 | - (void)viewDidLoad { [self.view addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(pasteBoard:)]]; } - (void)pasteBoard:(UILongPressGestureRecognizer *)longPress { if (longPress.state == UIGestureRecognizerStateBegan) { UIPasteboard *pasteboard = [UIPasteboard generalPasteboard]; pasteboard.string = @ "需要复制的文本" ; } } |
50、cocoapods升级
在终端执行 sudo gem install -n / usr / local / bin cocoapods --pre
51、设置启动页后，依然显示之前的
删除app，手机重启，重新安装
52、判断图片类型
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | //通过图片Data数据第一个字节 来获取图片扩展名 - (NSString *)contentTypeForImageData:(NSData *)data { uint8_t c; [data getBytes:&c length:1]; switch (c) { case 0xFF: return @ "jpeg" ; case 0x89: return @ "png" ; case 0x47: return @ "gif" ; case 0x49: case 0x4D: return @ "tiff" ; case 0x52: if ([data length] < 12) { return nil; } NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding]; if ([testString hasPrefix:@ "RIFF" ] && [testString hasSuffix:@ "WEBP" ]) { return @ "webp" ; } return nil; } return nil; } |
53、获取手机和app信息
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary]; CFShow(infoDictionary); // app名称 NSString *app_Name = [infoDictionary objectForKey:@ "CFBundleDisplayName" ]; // app版本 NSString *app_Version = [infoDictionary objectForKey:@ "CFBundleShortVersionString" ]; // app build版本 NSString *app_build = [infoDictionary objectForKey:@ "CFBundleVersion" ]; //手机序列号 NSString* identifierNumber = [[UIDevice currentDevice] uniqueIdentifier]; NSLog(@ "手机序列号: %@" ,identifierNumber); //手机别名： 用户定义的名称 NSString* userPhoneName = [[UIDevice currentDevice] name]; NSLog(@ "手机别名: %@" , userPhoneName); //设备名称 NSString* deviceName = [[UIDevice currentDevice] systemName]; NSLog(@ "设备名称: %@" ,deviceName ); //手机系统版本 NSString* phoneVersion = [[UIDevice currentDevice] systemVersion]; NSLog(@ "手机系统版本: %@" , phoneVersion); //手机型号 NSString* phoneModel = [[UIDevice currentDevice] model]; NSLog(@ "手机型号: %@" ,phoneModel ); //地方型号 （国际化区域名称） NSString* localPhoneModel = [[UIDevice currentDevice] localizedModel]; NSLog(@ "国际化区域名称: %@" ,localPhoneModel ); NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary]; // 当前应用名称 NSString *appCurName = [infoDictionary objectForKey:@ "CFBundleDisplayName" ]; NSLog(@ "当前应用名称：%@" ,appCurName); // 当前应用软件版本 比如：1.0.1 NSString *appCurVersion = [infoDictionary objectForKey:@ "CFBundleShortVersionString" ]; NSLog(@ "当前应用软件版本:%@" ,appCurVersion); // 当前应用版本号码 int类型 NSString *appCurVersionNum = [infoDictionary objectForKey:@ "CFBundleVersion" ]; NSLog(@ "当前应用版本号码：%@" ,appCurVersionNum); |
54、获取一个类的所有属性
| 1 2 3 4 5 6 7 | id LenderClass = objc_getClass( "Lender" ); unsigned int outCount, i; objc_property_t *properties = class_copyPropertyList(LenderClass, &outCount); for (i = 0; i < outCount; i++) { objc_property_t property = properties[i]; fprintf(stdout, "%s %s\n" , property_getName(property), property_getAttributes(property)); } |
55、image圆角
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | - (UIImage *)circleImage { // NO代表透明 UIGraphicsBeginImageContextWithOptions(self.size, NO, 1); // 获得上下文 CGContextRef ctx = UIGraphicsGetCurrentContext(); // 添加一个圆 CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height); // 方形变圆形 CGContextAddEllipseInRect(ctx, rect); // 裁剪 CGContextClip(ctx); // 将图片画上去 [self drawInRect:rect]; UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return image; } |
56、image拉伸
| 1 2 3 4 5 6 7 | + (UIImage *)resizableImage:(NSString *)imageName { UIImage *image = [UIImage imageNamed:imageName]; CGFloat imageW = image.size.width; CGFloat imageH = image.size.height; return [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageH * 0.5, imageW * 0.5, imageH * 0.5, imageW * 0.5) resizingMode:UIImageResizingModeStretch]; } |
57、JSON字符串转字典
| 1 2 3 4 5 | + (NSDictionary *)parseJSONStringToNSDictionary:(NSString *)JSONString { NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding]; NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil]; return responseJSON; } |
58、身份证号验证
| 1 2 3 4 5 6 7 8 9 10 | - (BOOL)validateIdentityCard { BOOL flag; if (self.length <= 0) { flag = NO; return flag; } NSString *regex2 = @ "^(\\d{14}|\\d{17})(\\d|[xX])$" ; NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@ "SELF MATCHES %@" ,regex2]; return [identityCardPredicate evaluateWithObject:self]; } |
59、获取设备mac地址
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | + (NSString *)macAddress { int mib[6]; size_t len; char *buf; unsigned char *ptr; struct if_msghdr *ifm; struct sockaddr_dl *sdl; mib[0] = CTL_NET; mib[1] = AF_ROUTE; mib[2] = 0; mib[3] = AF_LINK; mib[4] = NET_RT_IFLIST; if ((mib[5] = if_nametoindex( "en0" )) == 0) { printf( "Error: if_nametoindex error\n" ); return NULL; } if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) { printf( "Error: sysctl, take 1\n" ); return NULL; } if ((buf = malloc(len)) == NULL) { printf( "Could not allocate memory. Rrror!\n" ); return NULL; } if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) { printf( "Error: sysctl, take 2" ); return NULL; } ifm = (struct if_msghdr *)buf; sdl = (struct sockaddr_dl *)(ifm + 1); ptr = (unsigned char *)LLADDR(sdl); NSString *outstring = [NSString stringWithFormat:@ "X:X:X:X:X:X" , *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)]; free(buf); return outstring; } |
60、导入自定义字体库
-
1、找到你想用的字体的 ttf 格式，拖入工程
-
2、在工程的plist中增加一行数组，“Fonts provided by application”
-
3、为这个key添加一个item，value为你刚才导入的ttf文件名
-
4、直接使用即可：label.font = [UIFont fontWithName:@"你刚才导入的ttf文件名" size:20.0]；
61、拿到当前正在显示的控制器，不管是push进去的，还是present进去的都能拿到
| 1 2 3 4 5 6 7 8 9 10 11 12 13 | - (UIViewController *)getVisibleViewControllerFrom:(UIViewController*)vc { if ([vc isKindOfClass:[UINavigationController class]]) { return [self getVisibleViewControllerFrom:[((UINavigationController*) vc) visibleViewController]]; } else if ([vc isKindOfClass:[UITabBarController class]]){ return [self getVisibleViewControllerFrom:[((UITabBarController*) vc) selectedViewController]]; } else { if (vc.presentedViewController) { return [self getVisibleViewControllerFrom:vc.presentedViewController]; } else { return vc; } } } |
62、runtime为一个类动态添加属性
| 1 2 | // 动态添加属性的本质是: 让对象的某个属性与值产生关联 objc_setAssociatedObject(self, WZBPlaceholderViewKey, placeholderView, OBJC_ASSOCIATION_RETAIN_NONATOMIC); |
63、获取runtime为一个类动态添加的属性
| 1 | objc_getAssociatedObject(self, WZBPlaceholderViewKey); |
64、KVO监听某个对象的属性
| 1 2 3 4 5 6 7 8 9 10 | // 添加监听者 [self addObserver:self forKeyPath:property options:NSKeyValueObservingOptionNew context:nil]; // 当监听的属性值变化的时候会来到这个方法 - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context { if ([keyPath isEqualToString:@ "property" ]) { [self textViewTextChange]; } else { } } |
65、Reachability判断网络状态
| 1 2 3 4 5 6 7 8 9 10 | NetworkStatus status = [[Reachability reachabilityForInternetConnection] currentReachabilityStatus]; if (status == NotReachable) { NSLog(@ "当前设备无网络" ); } if (status == ReachableViaWiFi) { NSLog(@ "当前wifi网络" ); } if (status == NotReachable) { NSLog(@ "当前蜂窝移动网络" ); } |
66、AFNetworking监听网络状态
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | // 监听网络状况 AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager]; [mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) { switch (status) { case AFNetworkReachabilityStatusUnknown: break ; case AFNetworkReachabilityStatusNotReachable: { [SVProgressHUD showInfoWithStatus:@ "当前设备无网络" ]; } break ; case AFNetworkReachabilityStatusReachableViaWiFi: [SVProgressHUD showInfoWithStatus:@ "当前Wi-Fi网络" ]; break ; case AFNetworkReachabilityStatusReachableViaWWAN: [SVProgressHUD showInfoWithStatus:@ "当前蜂窝移动网络" ]; break ; default : break ; } }]; [mgr startMonitoring]; |
67、透明颜色不影响子视图透明度
| 1 | [UIColor colorWithRed: green: blue: alpha:]; |
68、取图片某一点的颜色
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | if (point.x < 0 || point.y < 0) return nil; CGImageRef imageRef = self.CGImage; NSUInteger width = CGImageGetWidth(imageRef); NSUInteger height = CGImageGetHeight(imageRef); if (point.x >= width || point.y >= height) return nil; unsigned char *rawData = malloc(height * width * 4); if (!rawData) return nil; CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); NSUInteger bytesPerPixel = 4; NSUInteger bytesPerRow = bytesPerPixel * width; NSUInteger bitsPerComponent = 8; CGContextRef context = CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); if (!context) { free(rawData); return nil; } CGColorSpaceRelease(colorSpace); CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef); CGContextRelease(context); int byteIndex = (bytesPerRow * point.y) + point.x * bytesPerPixel; CGFloat red = (rawData[byteIndex] * 1.0) / 255.0; CGFloat green = (rawData[byteIndex + 1] * 1.0) / 255.0; CGFloat blue = (rawData[byteIndex + 2] * 1.0) / 255.0; CGFloat alpha = (rawData[byteIndex + 3] * 1.0) / 255.0; UIColor *result = nil; result = [UIColor colorWithRed:red green:green blue:blue alpha:alpha]; free(rawData); return result; |
69、判断该图片是否有透明度通道
| 1 2 3 4 5 6 7 8 | - (BOOL)hasAlphaChannel { CGImageAlphaInfo alpha = CGImageGetAlphaInfo(self.CGImage); return (alpha == kCGImageAlphaFirst || alpha == kCGImageAlphaLast || alpha == kCGImageAlphaPremultipliedFirst || alpha == kCGImageAlphaPremultipliedLast); } |
70、获得灰度图
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | + (UIImage*)covertToGrayImageFromImage:(UIImage*)sourceImage { int width = sourceImage.size.width; int height = sourceImage.size.height; CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray(); CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone); CGColorSpaceRelease(colorSpace); if (context == NULL) { return nil; } CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage); CGImageRef contextRef = CGBitmapContextCreateImage(context); UIImage *grayImage = [UIImage imageWithCGImage:contextRef]; CGContextRelease(context); CGImageRelease(contextRef); return grayImage; } |
71、根据bundle中的文件名读取图片
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | + (UIImage *)imageWithFileName:(NSString *)name { NSString *extension = @ "png" ; NSArray *components = [name componentsSeparatedByString:@ "." ]; if ([components count] >= 2) { NSUInteger lastIndex = components.count - 1; extension = [components objectAtIndex:lastIndex]; name = [name substringToIndex:(name.length-(extension.length+1))]; } // 如果为Retina屏幕且存在对应图片，则返回Retina图片，否则查找普通图片 if ([UIScreen mainScreen].scale == 2.0) { name = [name stringByAppendingString:@ "@2x" ]; NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension]; if (path != nil) { return [UIImage imageWithContentsOfFile:path]; } } if ([UIScreen mainScreen].scale == 3.0) { name = [name stringByAppendingString:@ "@3x" ]; NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension]; if (path != nil) { return [UIImage imageWithContentsOfFile:path]; } } NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension]; if (path) { return [UIImage imageWithContentsOfFile:path]; } return nil; } |
72、合并两个图片
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | + (UIImage*)mergeImage:(UIImage*)firstImage withImage:(UIImage*)secondImage { CGImageRef firstImageRef = firstImage.CGImage; CGFloat firstWidth = CGImageGetWidth(firstImageRef); CGFloat firstHeight = CGImageGetHeight(firstImageRef); CGImageRef secondImageRef = secondImage.CGImage; CGFloat secondWidth = CGImageGetWidth(secondImageRef); CGFloat secondHeight = CGImageGetHeight(secondImageRef); CGSize mergedSize = CGSizeMake(MAX(firstWidth, secondWidth), MAX(firstHeight, secondHeight)); UIGraphicsBeginImageContext(mergedSize); [firstImage drawInRect:CGRectMake(0, 0, firstWidth, firstHeight)]; [secondImage drawInRect:CGRectMake(0, 0, secondWidth, secondHeight)]; UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return image; } |
73、根据bundle中的图片名创建imageview
| 1 2 3 4 | + (id)imageViewWithImageNamed:(NSString*)imageName { return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]]; } |
74、为imageView添加倒影
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | CGRect frame = self.frame; frame.origin.y += (frame.size.height + 1); UIImageView *reflectionImageView = [[UIImageView alloc] initWithFrame:frame]; self.clipsToBounds = TRUE; reflectionImageView.contentMode = self.contentMode; [reflectionImageView setImage:self.image]; reflectionImageView.transform = CGAffineTransformMakeScale(1.0, -1.0); CALayer *reflectionLayer = [reflectionImageView layer]; CAGradientLayer *gradientLayer = [CAGradientLayer layer]; gradientLayer.bounds = reflectionLayer.bounds; gradientLayer.position = CGPointMake(reflectionLayer.bounds.size.width / 2, reflectionLayer.bounds.size.height * 0.5); gradientLayer.colors = [NSArray arrayWithObjects: (id)[[UIColor clearColor] CGColor], (id)[[UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.3] CGColor], nil]; gradientLayer.startPoint = CGPointMake(0.5,0.5); gradientLayer.endPoint = CGPointMake(0.5,1.0); reflectionLayer.mask = gradientLayer; [self.superview addSubview:reflectionImageView]; |
75、画水印
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | // 画水印 - (void) setImage:(UIImage *)image withWaterMark:(UIImage *)mark inRect:(CGRect)rect { if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0) { UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, 0.0); } //原图 [image drawInRect:self.bounds]; //水印图 [mark drawInRect:rect]; UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); self.image = newPic; } |
76、让label的文字内容显示在左上／右上／左下／右下／中心顶／中心底部
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 | 自定义UILabel // 重写label的textRectForBounds方法 - (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines { CGRect rect = [ super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines]; switch (self.textAlignmentType) { case WZBTextAlignmentTypeLeftTop: { rect.origin = bounds.origin; } break ; case WZBTextAlignmentTypeRightTop: { rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, bounds.origin.y); } break ; case WZBTextAlignmentTypeLeftBottom: { rect.origin = CGPointMake(bounds.origin.x, CGRectGetMaxY(bounds) - rect.size.height); } break ; case WZBTextAlignmentTypeRightBottom: { rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, CGRectGetMaxY(bounds) - rect.size.height); } break ; case WZBTextAlignmentTypeTopCenter: { rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - rect.origin.y); } break ; case WZBTextAlignmentTypeBottomCenter: { rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - CGRectGetMaxY(bounds) - rect.size.height); } break ; case WZBTextAlignmentTypeLeft: { rect.origin = CGPointMake(0, rect.origin.y); } break ; case WZBTextAlignmentTypeRight: { rect.origin = CGPointMake(rect.origin.x, 0); } break ; case WZBTextAlignmentTypeCenter: { rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, (CGRectGetHeight(bounds) - CGRectGetHeight(rect)) / 2); } break ; default : break ; } return rect; } - (void)drawTextInRect:(CGRect)rect { CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines]; [ super drawTextInRect:textRect]; } |
77、scrollView上的输入框，键盘挡住的问题
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | 推荐用IQKeyboardManager这个框架！ 手动解决如下 1、监听键盘弹出／消失的通知 2、在通知中加入代码： NSDictionary* info = [aNotification userInfo]; CGRect keyPadFrame=[[UIApplication sharedApplication].keyWindow convertRect:[[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue] fromView:self.view]; CGSize kbSize =keyPadFrame.size; CGRect activeRect=[self.view convertRect:activeField.frame fromView:activeField.superview]; CGRect aRect = self.view.bounds; aRect.size.height -= (kbSize.height); CGPoint origin = activeRect.origin; origin.y -= backScrollView.contentOffset.y; if (!CGRectContainsPoint(aRect, origin)) { CGPoint scrollPoint = CGPointMake(0.0,CGRectGetMaxY(activeRect)-(aRect.size.height)); [backScrollView setContentOffset:scrollPoint animated:YES]; } |
78、frame布局的cell动态高度
这种通常在你的模型中添加一个辅助属性cellHeight，在模型中重写这个属性的get方法，根据你的布局和模型中的其他属性值计算出总高度。最后在tableView：heightForRow方法中，根据indexPath找出对应的模型，返回这个高度即可。
79、AutoLayout布局的cell动态高度
| 1 2 3 4 | // 1、设置tableView的属性 self.tableView.rowHeight = UITableViewAutomaticDimension; self.tableView.estimatedRowHeight = 44.0; // 这个属性非0，估计cell高度 // 2、至上而下设置cell的约束，注意，上下左右最好都要顶到cell的四周 |
cell
80、使用performSelector:调用函数，内存泄漏问题
当我们在开发中使用[obj performSelector:NSSelectorFromString(@"aMethod")];这类方法时可能会收到一个警告"performSelector may cause a leak because its selector is unknown".
是因为编译器不清楚这个对象能不能相应这个方法，如果不能，则是不安全的，而且编译器也不清楚该怎么处理这个方法的返回值！
| 1 2 3 4 5 6 7 8 9 10 | 使用以下代码调用即可： if (! obj) { return ; } SEL selector = NSSelectorFromString(@ "aMethod" ); IMP imp = [obj methodForSelector:selector]; void (*func)(id, SEL) = (void *)imp; func(obj, selector); 或者： SEL selector = NSSelectorFromString(@ "aMethod" ); ((void (*)(id, SEL))[obj methodForSelector:selector])(obj, selector); |
81、一个字符串是否包含另一个字符串
| 1 2 3 4 5 6 7 8 9 10 11 12 13 | // 方法1 if ([str1 containsString:str2]) { NSLog(@ "str1包含str2" ); } else { NSLog(@ "str1不包含str2" ); } // 方法2 if ([str1 rangeOfString: str2].location == NSNotFound) { NSLog(@ "str1包含str2" ); } else { NSLog(@ "str1不包含str2" ); } |
82、cell去除选中效果
| 1 | cell.selectionStyle = UITableViewCellSelectionStyleNone; |
83、cell点按效果
| 1 2 3 | - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { [tableView deselectRowAtIndexPath:indexPath animated:YES]; } |
84、当删除一个从xib拖出来的属性时，一定记得把xib中对应的线也删掉，不然会报类似[setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key的crash
点击这个叉号删除
85、真机测试的时候报错：Could not launch "你的 App"，process launch failed: Security
因为你的app没有上线，iOS9开始，需要手动信任Xcode生成的描述文件，打开手机设置->通用->描述文件->点击你的app的描述文件->点击信任
86、真机测试的时候报错：Could not find Developer Disk Image
这是因为你的设备系统版本大于Xcode能兼容的系统版本，比如你的设备是iOS10.3，而Xcode版本是8.2（Xcode8.2最大兼容iOS10.2），就会报这个错误。解决办法就是升级Xcode！
87、UITextView没有placeholder的问题？
网上有很多此类自定义控件，也可以参考下我写的一个UITextView分类 UITextView-WZB
88、移除字符串中的空格和换行
| 1 2 3 4 5 6 | + (NSString *)removeSpaceAndNewline:(NSString *)str { NSString *temp = [str stringByReplacingOccurrencesOfString:@ " " withString:@ "" ]; temp = [temp stringByReplacingOccurrencesOfString:@ "\r" withString:@ "" ]; temp = [temp stringByReplacingOccurrencesOfString:@ "\n" withString:@ "" ]; return temp; } |
89、判断字符串中是否有空格
| 1 2 3 4 5 6 7 8 9 10 | + (BOOL)isBlank:(NSString *)str { NSRange _range = [str rangeOfString:@ " " ]; if (_range.location != NSNotFound) { //有空格 return YES; } else { //没有空格 return NO; } } |
90、获取一个视频的第一帧图片
| 1 2 3 4 5 6 7 8 9 10 | NSURL *url = [NSURL URLWithString:filepath]; AVURLAsset *asset1 = [[AVURLAsset alloc] initWithURL:url options:nil]; AVAssetImageGenerator *generate1 = [[AVAssetImageGenerator alloc] initWithAsset:asset1]; generate1.appliesPreferredTrackTransform = YES; NSError *err = NULL; CMTime time = CMTimeMake(1, 2); CGImageRef oneRef = [generate1 copyCGImageAtTime:time actualTime:NULL error:&err]; UIImage *one = [[UIImage alloc] initWithCGImage:oneRef]; return one; |
91、获取视频的时长
| 1 2 3 4 5 6 7 | + (NSInteger)getVideoTimeByUrlString:(NSString *)urlString { NSURL *videoUrl = [NSURL URLWithString:urlString]; AVURLAsset *avUrl = [AVURLAsset assetWithURL:videoUrl]; CMTime time = [avUrl duration]; int seconds = ceil(time.value/time.timescale); return seconds; } |
92、字符串是否为空
| 1 2 3 | + (BOOL)isEqualToNil:(NSString *)str { return str.length <= 0 || [str isEqualToString:@ "" ] || !str; } |
93、将app上传到App Store的时候通常会遇到这个问题
try again
很多人说这事苹果爸爸服务器问题，重复尝试几次，总会成功的！
但是经过尝试发现如果使用Application Loader上传成功率就非常高，所以还是推荐把ipa文件导出直接用Application Loader上传。
如果Application Loader也不行，需要检查下自己的网络，有时候vpn也会提高速度。
94、当tableView占不满一屏时，去除下边多余的单元格
| 1 2 | self.tableView.tableHeaderView = [UIView new ]; self.tableView.tableFooterView = [UIView new ]; |
95、isKindOfClass和isMemberOfClass的区别
| 1 2 | isKindOfClass可以判断某个对象是否属于某个类，或者这个类的子类。 isMemberOfClass更加精准，它只能判断这个对象类型是否为这个类(不能判断子类) |
96、__block
当一个局部变量需要在block里改变时，需要在定义时加上__block修饰，具体请看官方文档 .html#//apple_ref/doc/uid/TP40007502-CH6-SW6
97、-[ViewController aMethod:]: unrecognized selector sent to instance 0x7fe91e607fb0
这是一个经典错误，ViewController不能响应aMethod这个方法，错误原因可能viewController文件中没有实现aMethod这个方法
98、UITableView () failed to obtain a cell from its dataSource ()
这个错误原因是tableView的代理方法-tableView:cellForRowAtIndexPath:需要返回一个UITableViewCell,而你返回了一个nil。另外这个地方返回值不是UITableViewCell类型也会导致崩溃
99、约束如何做UIView动画？
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1、把需要改的约束Constraint拖条线出来，成为属性
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2、在需要动画的地方加入代码，改变此属性的constant属性
-
3、开始做UIView动画，动画里边调用layoutIfNeeded方法
| 1 2 3 4 5 | @property (weak, nonatomic) IBOutlet NSLayoutConstraint *buttonTopConstraint; self.buttonTopConstraint.constant = 100; [UIView animateWithDuration:.5 animations:^{ [self.view layoutIfNeeded]; }]; |
100、从NSURL中拿到链接字符串
| 1 | NSString *urlString = myURL.absoluteString; |
101、将tableView滚动到顶部
| 1 2 3 | [tableView setContentOffset:CGPointZero animated:YES]; 或者 [tableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:YES]; |
102、如果用addTarget:action:forControlEvents:方法为一个button添加了很多点击事件，在某个时刻想一次删除怎么办？只需要调用下边这句代码
| 1 | [youButton removeTarget:nil action:nil forControlEvents:UIControlEventAllEvents]; |
103、某个字体的高度
| 1 | font.lineHeight; |
104、删除某个view所有的子视图
| 1 2 | [[someView subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)]; |
105、删除NSUserDefaults所有记录
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 | //方法一 NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier]; [[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain]; //方法二 - (void)resetDefaults { NSUserDefaults * defs = [NSUserDefaults standardUserDefaults]; NSDictionary * dict = [defs dictionaryRepresentation]; for (id key in dict) { [defs removeObjectForKey:key]; } [defs synchronize]; } // 方法三 [[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]]; |
106、禁用系统滑动返回功能
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | - (void)viewDidAppear:(BOOL)animated { [ super viewDidAppear:animated]; if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = self; } } - (void)viewWillDisappear:(BOOL)animated { [ super viewWillDisappear:animated]; if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = nil; } } - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer { return NO; } |
107、模拟器报错
模拟器报错
解决办法：
打开模拟器->Simulator->Reset Content and Settings...
如果不行，就重启试试！
108、自定义cell选中背景颜色
| 1 2 3 | UIView *bgColorView = [[UIView alloc] init]; bgColorView.backgroundColor = [UIColor redColor]; [cell setSelectedBackgroundView:bgColorView]; |
109、UILabel设置内边距
| 1 2 3 4 5 6 | 子类化UILabel，重写drawTextInRect方法 - (void)drawTextInRect:(CGRect)rect { // 边距，上左下右 UIEdgeInsets insets = {0, 5, 0, 5}; [ super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)]; } |
110、UILabel设置文字描边
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | 子类化UILabel，重写drawTextInRect方法 - (void)drawTextInRect:(CGRect)rect { CGContextRef c = UIGraphicsGetCurrentContext(); // 设置描边宽度 CGContextSetLineWidth(c, 1); CGContextSetLineJoin(c, kCGLineJoinRound); CGContextSetTextDrawingMode(c, kCGTextStroke); // 描边颜色 self.textColor = [UIColor redColor]; [ super drawTextInRect:rect]; // 文本颜色 self.textColor = [UIColor yellowColor]; CGContextSetTextDrawingMode(c, kCGTextFill); [ super drawTextInRect:rect]; } |
111、使用模拟器截图
| 1 2 | 快捷键command + s 或者File->Save Screen Shot |
112、scrollView滚动到最下边
| 1 2 | CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height); [scrollView setContentOffset:bottomOffset animated:YES]; |
113、UIView背景颜色渐变
| 1 2 3 4 5 6 | UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)]; [self.view addSubview:view]; CAGradientLayer *gradient = [CAGradientLayer layer]; gradient.frame = view.bounds; gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil]; [view.layer insertSublayer:gradient atIndex:0]; |
114、停止UIView动画
| 1 | [yourView.layer removeAllAnimations] |
115、为UIView某个角添加圆角
| 1 2 3 4 5 6 | // 左上角和右下角添加圆角 UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomRight) cornerRadii:CGSizeMake(20, 20)]; CAShapeLayer *maskLayer = [CAShapeLayer layer]; maskLayer.frame = view.bounds; maskLayer.path = maskPath.CGPath; view.layer.mask = maskLayer; |
116、删除Xcode Derived data缓存数据
依次点击Xcode -> Preferences -> location，然后点击 Derived data路径后到小箭头，删除这个文件夹下的数据就可以了，如图
Xcode Derived data
117、将一个view放置在其兄弟视图的最上面
| 1 | [parentView bringSubviewToFront:yourView] |
118、将一个view放置在其兄弟视图的最下面
| 1 | [parentView sendSubviewToBack:yourView] |
119、让手机震动一下
| 1 2 3 4 5 | 倒入框架 #import AudioServicesPlayAlertSound(kSystemSoundID_Vibrate); 或者 AudioServicesPlaySystemSound(kSystemSoundID_Vibrate); |
120、layoutSubviews方法什么时候调用？
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1、init方法不会调用
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2、addSubview方法等时候会调用
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3、bounds改变的时候调用
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4、scrollView滚动的时候会调用scrollView的layoutSubviews方法(所以不建议在scrollView的layoutSubviews方法中做复杂逻辑)
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5、旋转设备的时候调用
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6、子视图被移除的时候调用
参考请看：/
121、让UILabel在指定的地方换行
| 1 2 3 | // 换行符为\n,在需要换行的地方加上这个符号即可，如 label.numberOfLines = 0; label.text = @ "此处\n换行" ; |
122、摇一摇功能
| 1 2 3 4 5 6 7 8 9 10 11 12 | 1、打开摇一摇功能 [UIApplication sharedApplication].applicationSupportsShakeToEdit = YES; 2、让需要摇动的控制器成为第一响应者 [self becomeFirstResponder]; 3、实现以下方法 // 开始摇动 - (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event // 取消摇动 - (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event // 摇动结束 - (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event |
123、获取图片大小
| 1 2 | CGFloat imageWidth = image.size.width; CGFloat imageHeight = imageWidth * image.scale; |
124、获取view的坐标在整个window上的位置
| 1 2 3 4 | // v上的(0, 0)点在toView上的位置 CGPoint point = [v convertPoint:CGPointMake(0, 0) toView:[UIApplication sharedApplication].windows.lastObject]; 或者 CGPoint point = [v.superview convertPoint:v.frame.origin toView:[UIApplication sharedApplication].windows.lastObject]; |
125、提交App Store审核程序限制
您的应用程序的未压缩大小必须小于4GB。每个Mach-O可执行文件（例如app_name.app/app_name）不能超过这些限制：
对于MinimumOSVersion小于7.0的应用程序：TEXT二进制文件中所有部分的总数最多为80 MB 。
对于MinimumOSVersion7.x到8.x的应用程序：TEXT对于二进制文件中每个体系结构片段的每个片段，最大为60 MB 。
对于MinimumOSVersion9.0或更高版本的应用程序：__TEXT二进制文件中所有部分的总数最多为500 MB 。参阅：iTunes Connect开发者指南
126、修改UISegmentedControl的字体大小
| 1 | [segment setTitleTextAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15.0f]} forState:UIControlStateNormal]; |
127、在非ViewController的地方弹出UIAlertController对话框
| 1 2 3 4 5 6 7 8 9 10 11 12 13 | // 最好抽成一个分类 UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@ "Title" message:@ "message" preferredStyle:UIAlertControllerStyleAlert]; //... id rootViewController = [UIApplication sharedApplication].delegate.window.rootViewController; if ([rootViewController isKindOfClass:[UINavigationController class]]) { rootViewController = ((UINavigationController *)rootViewController).viewControllers.firstObject; } if ([rootViewController isKindOfClass:[UITabBarController class]]) { rootViewController = ((UITabBarController *)rootViewController).selectedViewController; } [rootViewController presentViewController:alertController animated:YES completion:nil]; |
128、获取一个view所属的控制器
| 1 2 3 4 5 6 7 8 9 10 | // view分类方法 - (UIViewController *)belongViewController { for (UIView *next = [self superview]; next; next = next.superview) { UIResponder* nextResponder = [next nextResponder]; if ([nextResponder isKindOfClass:[UIViewController class]]) { return (UIViewController *)nextResponder; } } return nil; } |
129、UIImage和base64互转
| 1 2 3 4 5 6 7 8 9 | // view分类方法 - (NSString *)encodeToBase64String:(UIImage *)image { return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength]; } - (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData { NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters]; return [UIImage imageWithData:data]; } |
130、UIWebView设置背景透明
| 1 2 | [webView setBackgroundColor:[UIColor clearColor]]; [webView setOpaque:NO]; |
131、判断NSDate是不是今天
| 1 2 3 4 5 6 7 8 | NSDateComponents *otherDay = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:aDate]; NSDateComponents *today = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:[NSDate date]]; if ([today day] == [otherDay day] && [today month] == [otherDay month] && [today year] == [otherDay year] && [today era] == [otherDay era]) { // 是今天 } |
132、设置tableView分割线颜色
| 1 | [self.tableView setSeparatorColor:[UIColor myColor]]; |
133、设置屏幕方向
| 1 | [[UIDevice currentDevice] setValue:@(UIInterfaceOrientationLandscapeLeft) forKey:@ "orientation" ]; |
134、比较两个颜色是否相等
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | - (BOOL)isEqualToColor:(UIColor *)otherColor { CGColorSpaceRef colorSpaceRGB = CGColorSpaceCreateDeviceRGB(); 6 UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color) { if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == kCGColorSpaceModelMonochrome) { const CGFloat *oldComponents = CGColorGetComponents(color.CGColor); CGFloat components[4] = {oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]}; CGColorRef colorRef = CGColorCreate( colorSpaceRGB, components ); 6 UIColor *color = [UIColor colorWithCGColor:colorRef]; CGColorRelease(colorRef); return color; } else return color; }; 6 UIColor *selfColor = convertColorToRGBSpace(self); otherColor = convertColorToRGBSpace(otherColor); CGColorSpaceRelease(colorSpaceRGB); return [selfColor isEqual:otherColor]; } |
135、tableViewCell分割线顶到头
| 1 2 3 4 5 6 7 8 9 10 | - (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath { [cell setSeparatorInset:UIEdgeInsetsZero]; [cell setLayoutMargins:UIEdgeInsetsZero]; cell.preservesSuperviewLayoutMargins = NO; } - (void)viewDidLayoutSubviews { [self.tableView setSeparatorInset:UIEdgeInsetsZero]; [self.tableView setLayoutMargins:UIEdgeInsetsZero]; } |
136、不让控制器的view随着控制器的xib拉伸或压缩
| 1 | self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight; |
137、cocoaPods报错 : [!] Unable to add a source with url .git named master-1.
You can try adding it manually in ~/.cocoapods/repos or via pod repo add.
解决方法：这是因为电脑里安装了另外一个Xcode导致cocoapods找不到路径了
在终端执行 sudo xcode-select -switch /Applications/Xcode.app 即可
138、安装cocoapods的时候出现 ERROR: While executing gem ... (Errno::EPERM)
| 1 | Operation not permitted - /usr/bin/pod |
解决办法：直接在终端执行 sudo gem install -n /usr/local/bin cocoapods
139、在状态栏增加网络请求的菊花，类似safari加载网页的时候状态栏菊花
| 1 | [UIApplication sharedApplication]workActivityIndicatorVisible = YES; |
140、检查一个rect是否包含一个point
| 1 2 | // point是否在rect内 BOOL isContains = CGRectContainsPoint(rect, point); |
141、在指定的宽度下，让UILabel自动设置最佳font
| 1 | label.adjustsFontSizeToFitWidth = YES; |
142、将一个image保存在相册中
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 | UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil); 或者 #import [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{ PHAssetChangeRequest *changeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image]; changeRequest.creationDate = [NSDate date]; } completionHandler:^(BOOL success, NSError *error) { if (success) { NSLog(@ "successfully saved" ); } else { NSLog(@ "error saving to photos: %@" , error); } }]; |
143、修改cell.imageView的大小
| 1 2 3 4 5 6 7 | UIImage *icon = [UIImage imageNamed:@ "" ]; CGSize itemSize = CGSizeMake(30, 30); UIGraphicsBeginImageContextWithOptions(itemSize, NO ,0.0); CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height); [icon drawInRect:imageRect]; cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); |
144、为一个view添加虚线边框
| 1 2 3 4 5 6 7 | CAShapeLayer *border = [CAShapeLayer layer]; border.strokeColor = [UIColor colorWithRed:67/255.0f green:37/255.0f blue:83/255.0f alpha:1].CGColor; border.fillColor = nil; border.lineDashPattern = @[@4, @2]; border.path = [UIBezierPath bezierPathWithRect:view.bounds].CGPath; border.frame = view.bounds; [view.layer addSublayer:border]; |
145、UITextView中打开或禁用复制，剪切，选择，全选等功能
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | // 继承UITextView重写这个方法 - (BOOL)canPerformAction:(SEL)action withSender:(id)sender { // 返回NO为禁用，YES为开启 // 粘贴 if (action == @selector(paste:)) return NO; // 剪切 if (action == @selector(cut:)) return NO; // 复制 if (action == @selector(copy:)) return NO; // 选择 if (action == @selector(select:)) return NO; // 选中全部 if (action == @selector(selectAll:)) return NO; // 删除 if (action == @selector( delete :)) return NO; // 分享 if (action == @selector(share)) return NO; return [ super canPerformAction:action withSender:sender]; } |
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